docs: Remove Lion reference

Library/Homebrew/env_config.rb

@@ -285,8 +285,7 @@ module Homebrew
         boolean:     true,
       },
       HOMEBREW_NO_EMOJI:                         {
-        description: "If set, do not print `HOMEBREW_INSTALL_BADGE` on a successful build." \
-                     "\n\n    *Note:* Will only try to print emoji on OS X Lion or newer.",
+        description: "If set, do not print `HOMEBREW_INSTALL_BADGE` on a successful build.",
         boolean:     true,
       },
       HOMEBREW_NO_ENV_HINTS:                     {

docs/Manpage.md

@@ -2192,8 +2192,6 @@ example, run `export HOMEBREW_NO_INSECURE_REDIRECT=1` rather than just
 - `HOMEBREW_NO_EMOJI`
   <br>If set, do not print `HOMEBREW_INSTALL_BADGE` on a successful build.
 
-    *Note:* Will only try to print emoji on OS X Lion or newer.
-
 - `HOMEBREW_NO_ENV_HINTS`
   <br>If set, do not print any hints about changing Homebrew's behaviour with environment variables.
 

manpages/brew.1

@@ -3220,9 +3220,6 @@ If set, disable all use of legacy compatibility code\.
 .br
 If set, do not print \fBHOMEBREW_INSTALL_BADGE\fR on a successful build\.
 .
-.IP
-\fINote:\fR Will only try to print emoji on OS X Lion or newer\.
-.
 .TP
 \fBHOMEBREW_NO_ENV_HINTS\fR
 .